Ethylene polymer compositions

Abstract

An ethylene polymer composition is provided that comprises: (a) bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, in an amount that is from about 0.0001 to less than 0.30 weight percent; and (b) at least one color stabilization compound selected from the group consisting of: (1) a carboxylic acid compound; (2) an alcohol compound; and (3) a hydroxycarboxylic acid compound; in an amount from about 0.0001 to about 1 weight percent; wherein said weight percents are based on the weight of said ethylene polymer composition.

That which is claimed is: 
     
       1. An ethylene polymer composition that comprises: (a) bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, in an amount that is from about 0.0001 to less than 0.30 weight percent; and   (b) at least one color stabilization compound selected from the group consisting of: (1) a carboxylic acid compound;   (2) an alcohol compound that has an aliphatic molecular structure; and (3) a hydroxycarboxylic acid compound;        in an amount from about 0.0001 to about 1 weight percent wherein said weight percents are based on the weight of said ethylene polymer.     
     
     
       2. A composition according to claim 1 wherein said ethylene polymer is a copolymer. 
     
     
       3. A composition according to claim 2 wherein said copolymer has a mono-1-olefin as a comonomer. 
     
     
       4. A composition according to claim 3 wherein said comonomer is selected from the group consisting of propylene, 1-butene, 3-methyl-1-butene, 1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene, 3-ethyl-1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene and mixtures of two or more said comonomers. 
     
     
       5. A composition according to claim 3 wherein said comonomer is 1-hexene. 
     
     
       6. A composition according to claim 1 wherein said ethylene polymer has a density greater than 0.94 grams per cubic centimeter and a melt index greater than 0.1 grams per ten minutes. 
     
     
       7. A composition according to claim 1 where the amount of said bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite is from about 0.001 to about 0.025 weight percent based on the weight of said ethylene polymer. 
     
     
       8. A composition according to claim 1 wherein said color stabilization compound is a carboxylic acid compound. 
     
     
       9. A composition according to claim 8 wherein said carboxylic acid compound has from one to about thirty carbon atoms in its molecular structure. 
     
     
       10. A composition according to claim 8 wherein said carboxylic acid compound has an aliphatic molecular structure. 
     
     
       11. A composition according to claim 8 wherein said carboxylic acid compound is selected from the group consisting of methanoic, ethanoic, propanoic, butanoic, pentanoic, hexanoic, heptanoic, octanoic, nonanoic, decanoic, dodocanoic, tetradecanoic, hexadecanoic, octadecanoic, ethanedioic, propenoic and mixtures of two or more of said carboxylic acid compounds. 
     
     
       12. A composition according to claim 8 wherein carboxylic acid compound is a saturated fatty acid that has from about 4 to about 22 carbon atoms. 
     
     
       13. A composition according to claim 8 wherein said carboxylic acid compound is selected from the group consisting of dodecanoic, hexadecanoic, octadecanoic and mixtures of two or more said carboxylic acid compounds. 
     
     
       14. A composition according to claim 8 wherein carboxylic acid compound is octadocanoic. 
     
     
       15. A composition according to claim 1 wherein said color stabilization compound is an alcohol compound that has an aliphatic molecular structure. 
     
     
       16. A composition according to claim 15 wherein said alcohol compound has from one to about 500 carbon atoms in its molecular structure. 
     
     
       17. A composition according to claim 15 wherein said alcohol compound has a straight-chain molecular structure with an alcohol group attached to one of the ends of the molecule. 
     
     
       18. A composition according to claim 15 wherein said alcohol compound is selected from the group consisting of methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol decanol, dodecanol, tetradecanol, hexadecanol, octadecanol, ethanediol, polyethylene glycol, and methoxypolyethylene glycol and mixtures of two or more of said alcohol compounds. 
     
     
       19. A composition according to claim 15 wherein said alcohol compound is a saturated alcohol that has from about 5 to about 50 carbon atoms. 
     
     
       20. A composition according to claim 15 wherein said alcohol compound is selected from the group consisting of polyethylene glycol, methoxypolyethylene glycol and mixtures of these alcohol compounds. 
     
     
       21. A composition according to claim 1 wherein said color stabilization compound is a hydroxycarboxylic acid compound. 
     
     
       22. A composition according to claim 21 wherein said hydroxycarboxylic acid has from one to about thirty carbon atoms in its molecular structure. 
     
     
       23. A composition according to claim 21 wherein said hydroxycarboxylic acid compound has an aliphatic molecular structure. 
     
     
       24. A composition according to claim 21 wherein said hydroxycarboxylic acid is selected from the group consisting of hydroxyethanoic, 2-hydroxypropanoic, hydroxybutanoic, 2,3-dihydroxypropanoic, hydroxypropanedioic, hydroxybutanedioic, 2,3-dihydroxybutanedioic, 2-hydroxy-1,2,3-propane tricarboxylic acid and mixtures of two or more said hydroxycarboxylic acids. 
     
     
       25. A composition according to claim 21 wherein said hydroxycarboxylic acid has at least one hydroxy group and one carboxylic acid group attached to the same carbon. 
     
     
       26. A composition according to claim 21 wherein said hydroxycarboxylic acid is 2-hydroxy-1,2,3-propane tricarboxylic acid. 
     
     
       27. A composition according to claim 1 wherein the amount of said color stabilization compound is from about 0.0005 to about 0.6 weight percent based on the weight of the ethylene polymer. 
     
     
       28. A composition according to claim 1 wherein the amount of said color stabilization agent is from 0.001 to 0.4 weight percent based on the weight of the ethylene polymer. 
     
     
       29. A ethylene copolymer composition that consists essentially of: (a) bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, in an amount that is from about 0.0001 to about 0.025 with percent; and   (b) a color stabilization compound that is 2-hydroxy-1,2,3-propane tricarboxylic acid, in an amount from about 0.001 to about 0.1 weight percent; wherein said weight percents are based on the weight of said ethylene copolymer.